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<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
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<body>
    <script>
        /* 
        ？： 0-1
        +:   reg>=1
        *:  0个 或 多个
        */
        var str ="jksdh2"
        var reg = /\d+/
        console.log(reg.test(str));
    </script>
</body>
</html>